Flash-board construction for dams.



F. W. SCHEIDE M.

FLASH BOARD CONSTRUC FOR DAMS.

PLICATION FILED JUNE [9| 1,202,228. Patented oat-24,1916.

awe MM FWSCHEIUENHELM FREDERICKW. SCHEIDENHE M, F r'ITTsBURGH,PENNSYLVANIA.

Specification of Letters Patent.

FLA SH-BOARD CONSTRUCTION FOR DAMS.

Patented Oct. 24, 1916;

Application fi1ed ll'une '19, 1915'. Serial no. 35,086.

To all whom it may concern vBe it known that I, FREDERICK \V. SoHEI-DENIIELM, a citizen of the'United States, re-

siding at Pittsburgh, in the countyv of Alleghenyand State ofPennsylvania, have invented certain new and useful Improvements in FlashBoard Construction for Dams, of which the following is a specification,reference being had to the accom-. panying drawings. e

The present invention pertains broadly to a new and useful improvementin flashboard construction for dams and has particular reference toimprovements in flash-' boards of theso-called collapsible type, whichare designed to fail in case the Water impounded by the dam rises to adangerous height.

It has been proposed in prior patents, and in some instances carriedinto practice, to equip the dam with a fiashboard which is adapted to,fail when the impounded water reaches a predetermined height, such 7failure being provided for by mounting the flashboard for swingingmovement and a0- companying it by springs or equivalent yieldableelements designedv to resist the swinging of the flashboard until thepressure of the impounded water reaches a predetermined point. p

The fiashboards of the collapsible type as hitherto built or designedhave, however, been found to be open to several objections. In the firstplace, the cost of installation 'is unduly great. Again, certainflashboards of this type (especially those supported by pins of the kindheretofore used) arenot adapted to :fail completely and reliably as soonas the water reaches a dangerous vheight but merely bend ortiltsomewhat,

allowing a part of the impounded water to flow over the dam but notentirely clearing the; crest of the dam or spillway. As a resultexcessive flood heights are not as effectively guarded against byfiashboards of the latter type as would be the case were the flashboardsdesigned to fail completely, allowing the impounded waterjto flow overthe spillway or crest of the dam I without any obstruction on part-,ofthe fiashboard or the fiashboa-rd supports.

In recognition of the above objections to the collapsible flashboards atpresent in use, it is, therefore, the principal object of the presentinvention to provide a fiashboard, and more particularly a flashboardsupport, which'is of utmost simplicity in construction, may bemanufactured and installed at an unusually small cost, and is designedto fail completely and wash over the crest of the dam at a predeterminedheight, thus allowing the impounded water to spill directly over thecrest of the dam until it subsides to a normal level.

A further and more specific object of the invention is to provide aflashboard which consists generally in a wall of suitable material and aplurality of supporting pins which are anchored at their lower ends inthe crest of the dam or spillway, and extending approximately to theheight of the fiashboard, are so constructed that they will maintain thewall in approximately its original position until the impounded waterreaches thepredetermined level, and will then snap or break ofi at thedam or spillway crest, thus permitting the impoiuidedwater to sweep theflashboard over the dam. A still further specific object of theinvention is the provision of fiashboard supports in the form of steelpins having a relatively high proportion of carbon in their compositionso that by proper hardening they become stiff and yet not too brittle,and will, therefore, resist any bending or flexing of the fiashboarduntil the water reaches the predetermined level, at which level thepressure of the impounded water against the flashboard will cause thepins to break or snap ofi'.

The above, and other incidental objects of a similar nature, which willbe hereinafter more specifically treated, are accomplished by suchmeansas are illustrated in the accompanying drawings, described in Y thefollowing specification, and then more particularly pointed out in theclaims whichare appended hereto and form a part of this application.

With reference to the drawing, wherein is illustrated thepreferredembodiment of the invention, as it is reduced to practice, the

figure is a transverse vertical section taken through the crest of thespillway section of a dam of the hollow type and illustrating theflashboard support of the present invention mounted {thereon andsupporting a wooden flashboard;

Before taking up the detailed description of the drawing, it is desiredto explain first that, while the flashboardsupport has been shown inconnection with a dam of the hollow type, it may, nevertheless, beemployed with equal efliciency with a solid dam since the particulardesign of the dam and the materials used in its construction are mattersof no consequence to the operation of the fiashboard support.

The flashboard, or wall, designated generally by the letter A, ismounted upon the lspillway crest of the dam B to extend longitudinallytherealong and in vertical alinement with the crest of the spillway. Inthis connection, it is to be particularly explained tliatwhile thefiashboard is preferably dis- 'posedin vertical alinement with thespillway rials which are employed in making the wall A are not withinthe scope of the present invention. The wall is, as shown,'supported orany other side of the pin.

in a vertical position by means of a plurality offround pinsll, whicharepreferably located against the 'down-st'reamface of the wall A. The pinsmaybe embedded in the wall in case this member is built of concrete ormay be passed through bores formed in the wall in case this member ismade of planking. Also, if desired and deemed expedient, the pins may bedisposed 011 the up-stream face of the member A and tied into thismember by any suitable means The pins need not necessarily be ofcircular cross section, but the circular crosssection is preferablebecause a round pin offers the same resistance to stress no matterwhether a given pointin the pin 11 is on the up-stream side or thedown-stream side The lower ends of the pins are inserted in the sockets12 preferably formedof pipe) in the spillway crest of the dam. In aninitialconstruction the sockets are embedded in the concrete at the timethe concrete is placed. NVhen the present invention is'applied to anexisting damin which no sockets havev previously been provided, however,proper-sockets are constructed bydrilling receiving bores in thespillway crest of the dam, in a manner which will be readily appreciatedby thoseskilled in the art. I desire now to explain that the method oftreating the supporting pins is a special feature of my invention. Inthe first place, the pins are made of steel whlch must contain arelatively large proportion of carbon. This is necessary because thepins are later to be hardened, which it is impossible to do if thecarbon content of the steel 15 too low. On the other hand, the carboncontent must not be too great, for with an excessive carbon contentthepins would become too brittle.

I prefer to use open hearth steel with a carbon content between 0.40%and v 0.80%. Likewise the sulfur and phosphorus contents of the'steelmust not be excessive, for excessive amounts of these constituents alsowillmake the pins too brittle for the purpose.- I preferthat the sulfurand phosphorus contents should each not exceed 0.05%.

Pins composed of steel of the chemical characteristics above describedare then hardened'by, first, heatingthem in a forge, or by othersuitable means, preferably to a cherry red color, and then promptlyplunging the bars thus heated into water 7 or othersuitable coolingliquid. Under ordinary conditions the'pins need to be hardened for onlyarelatively short distance, as shown in the figure at 13, above and below that point'in the pins which will (when in place) be opposite thetop of the socket 12, it being intended that the pins shall break orsnap off at the top of such sockets or anchorages. In special cases,however, it maybe advisable to thus harden the pins throughout thatportion of their length which projects above the socket or anchora ge,or even throughout their entire length.

The result of such hardening is that the pins will resist bending orflexing in themselves (and hence in the wall A) until the stress in thepins reaches such a point that the pins will fail by breaking orsnapping off. By proper control of the constituents of the steel ofwhich the pins are made, as hereinabove described, the pins will I breakat a predetermined stress and will not be so brittle that their behaviorwill be erratic and their breaking points not ap proximately uniform.The predetermined stress at which the pins will break, with little or noprevious permanent deflection, is's'uch that it will be developed by theimpounded water when the same has risen to the predetermined elevation.

It is to be noted that because of the fact that the projecting or upperportions of the pins 11 act as cantalivers, the stress in the pins isgreatest at the lower end of projecting'portion', viz, at the top of thesocket or anchorage. Hence it is at this point that the pins will break.The breaking or failure of the pins will, therefore, not merely allowthewall A to be, washed over the spillway crest of the dam, but willclear the spillway crest of any obstruction due to the pins Cirthemselves. The result is that the Spillway or flood dischargingcapacity of the dam is correspondingly increased. After the flood hassufficiently subsided, the lower ends of the pins still remaining in thesockets, or anchorages, are removed by using tongs, or other suitablemeans. New pins, of the same characteristics and previously hardened, asabove described, may then be inserted and a new wall A erected, or theoriginal wall A replaced, so as to again impound the water to thedesired elevation, greater than that of the spillway crest of the dam.

An advantage due to my invention should be particularly noted, namely,that the deflection in the supporting pins prior to breaking isnegligible in amount, and that, therefore, if the impounded water shouldrise to an elevation nearly equal to the elevation at which the pinswould break, but should thereupon subside to a normal level, theflashboard would resume approximately its original vertical position. Onthe other hand, supporting pins not hardened as above described wouldeitherhave been bent so much as not to return to their original position (and would, therefore, not be suitable for further use) or, if theyhad not deflected appreciably, would be. so strong that they would notbreak at so low an elevation of impounded water as would have caused thefailure of pins with the characteristics, and hardened, as abovedescribed.

The diameter of the round pins 11 and the carbon content thereof aresuitably proportioned according to the spacing of the pins 11, theheight of the wall A, the elevation of the impounded water at which itis intended that the pins (and hence the wall A) shall fail, and anyother pertinent conditions. It is immaterial whether or not thepredetermined water elevation, at which failure of the flashboard isintended to o'ccur, is such as to cause part of the impounded water toflow over the top of the flashboard.

While I have illustrated and described the flashboard support as beingparticularly adapted for use in supporting a fiashboard on the spillwaycrest of the dam, I desire it to be understood that the invention is notlimited to such application. Thus, such supports may be advantageouslyemployed in anchoring a temporary dam to its foundation, in order toprovide for the sudden failure of the dam when the impounded waterreaches a danger level, or in supporting a flashboard or otherobstruction in a channel or waterway likewise in order to provide forfailure under predetermined conditions.

lVhat is claimed, is

1. The combination with a supporting base, of a damming element mountedthereon, and a plurality of metallic pins secured at their lower ends inthe supporting base and engaging at their upper portions with thedamming element for holding the same against down-stream movement on thesup porting base, said pins being formed of relatively high carbonsteel, whereby they are stiff and brittle and are, therefore, adapted tosnap off, causing the failure of the damming element when the impoundedwater reaches a predetermined elevation.

2. The combination with a dam, of a flashboard consisting of a wallmounted on the dam to extend longitudinally on the crest thereof, and aplurality of metallic pins anchored at their lower ends in the dam, andengaging with the flashboard for anchoring the same in position on thedam, said pins being formed of relatively high carbon steel, wherebythey are brittle anr relatively inflexible so that they will rigidlyanchor the flashboard upon the dam until the moment at which theimpounded water reaches a predetermined elevation at which time the pinsare adapted to snap off by reason of their brittleness, to cause thefailure of the fiashboard and to permit this member to be carried ofithe dam in a downstream direction by the impounded water spilling overthe dam.

3. The combination with a supporting base, of a damming element mountedthereon, and a plurality of metallic pins secured at their lower ends inthe supporting base and engaging at their upper portions with thedamming element for holding the same against downstream movement on thesupporting base, said pins being formed of relatively high carbon steel,each of said pins being hardened at that portion which lies at andimmediately above and below the surface of the supporting base, byheating followed by immediate rapid cooling.

4. The combination with a supporting base, of a damming element mountedthereon, a plurality of sockets formed in the supporting base andopening through the upper surface thereof, and a plurality of metallicpins having their lower portions seated in the said sockets and theirupper portions engaging with the damming element for holding the sameagainst downstream movement on the base, said pins being formed ofrelatively high carbon steel, and being hardened by heating followed byimmediate rapid cooling, the hardened portions of the pins extending aslight distance above and below the upper surface of the supportingbase.

5. The combination with a supporting base of a damming element mountedthereon, a plurality of metallic sockets embedded in the supporting baseand opening through the upper surface thereof, and a plurality ofbrittle metallic pins having their lower a of said socket-s constitutingrigid abutments portions seated in--the, sockets and their upwhen thedamming element-is subjected to a 10 perfportions engaging the dammingelement predetermined down stream pressure. v

for supporting the same against down In testimony whereof I hereuntoaffix pmy stream movement on the base, the upper ends signature in thepresence oftwo Witnesses.

J! V FREDERICK W. SCHEIDENHELM- ior the intermedlate portlons of thePIIIS 1 7 whereby the pins will tend to snap off at Witnesses:

points located at or immediately adjacent to VVILLI-AM L. PAINE,

the upper surface of the supporting base H A. DUNN.

Copies of this patent msy be obtained for five cents eacihfny addressingthe Commissioner of Patents.

Washington, D. 0. v

